From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D7A8C4361A for ; Fri, 4 Dec 2020 18:35:17 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D1FBC22582 for ; Fri, 4 Dec 2020 18:35:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D1FBC22582 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=yadro.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:43950 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1klFvH-0000le-M9 for qemu-devel@archiver.kernel.org; Fri, 04 Dec 2020 13:35:15 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59506) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klEUQ-0005RK-3r; Fri, 04 Dec 2020 12:03:27 -0500 Received: from mta-02.yadro.com ([89.207.88.252]:45712 helo=mta-01.yadro.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1klETg-00045K-Fq; Fri, 04 Dec 2020 12:03:14 -0500 Received: from localhost (unknown [127.0.0.1]) by mta-01.yadro.com (Postfix) with ESMTP id 07098413F7; Fri, 4 Dec 2020 16:45:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yadro.com; h= in-reply-to:content-disposition:content-type:content-type :mime-version:references:message-id:subject:subject:from:from :date:date:received:received:received; s=mta-01; t=1607100301; x=1608914702; bh=UbfJ/R++S0L60KE+xUkKolPpBmDX+R7YWJSa5+nlIzY=; b= JLGNj2uQbuKZ+MlNwTyArg9BcoXlIvjND5tOqSJFhjdaKGKaqq3+Dfu+3jZW/f5K WneWeZD9bsOk3qCHxyqNAi8x6V6Xmver11fAJ8o9myW5wVDKdgGULcS3JOx82qw8 ion8YXvaKa+B4scdIwbgALRcojFMKGZ9cfPSfJN7kN0= X-Virus-Scanned: amavisd-new at yadro.com Received: from mta-01.yadro.com ([127.0.0.1]) by localhost (mta-01.yadro.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id XOyTdGIO5xOp; Fri, 4 Dec 2020 19:45:01 +0300 (MSK) Received: from T-EXCH-03.corp.yadro.com (t-exch-03.corp.yadro.com [172.17.100.103]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mta-01.yadro.com (Postfix) with ESMTPS id F317F41373; Fri, 4 Dec 2020 19:45:00 +0300 (MSK) Received: from localhost (172.17.204.212) by T-EXCH-03.corp.yadro.com (172.17.100.103) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.669.32; Fri, 4 Dec 2020 19:45:00 +0300 Date: Fri, 4 Dec 2020 19:45:23 +0300 From: Roman Bolshakov To: Alexander Graf Subject: Re: [PATCH v4 09/11] arm/hvf: Add a WFI handler Message-ID: <20201204164523.GH86904@SPB-NB-133.local> References: <20201203234857.21051-1-agraf@csgraf.de> <20201203234857.21051-10-agraf@csgraf.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20201203234857.21051-10-agraf@csgraf.de> X-Originating-IP: [172.17.204.212] X-ClientProxiedBy: T-EXCH-01.corp.yadro.com (172.17.10.101) To T-EXCH-03.corp.yadro.com (172.17.100.103) Received-SPF: pass client-ip=89.207.88.252; envelope-from=r.bolshakov@yadro.com; helo=mta-01.yadro.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Eduardo Habkost , Richard Henderson , qemu-devel@nongnu.org, Cameron Esfahani , qemu-arm@nongnu.org, Frank Yang , Paolo Bonzini , Peter Collingbourne Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Dec 04, 2020 at 12:48:55AM +0100, Alexander Graf wrote: > From: Peter Collingbourne > > Sleep on WFI until the VTIMER is due but allow ourselves to be woken > up on IPI. > > In this implementation IPI is blocked on the CPU thread at startup and > pselect() is used to atomically unblock the signal and begin sleeping. > The signal is sent unconditionally so there's no need to worry about > races between actually sleeping and the "we think we're sleeping" > state. It may lead to an extra wakeup but that's better than missing > it entirely. > Acked-by: Roman Bolshakov Thanks, Roman